A passive self-excited oscillation AC low-voltage energy harvesting circuit without a bridge

Abstract

Most current electromagnetic energy harvesters use capacitor voltage multipliers or boost circuits controlled by external signals to step up and store energy. However, for most low-voltage output electromagnetic energy harvesters, generating switching control signals and rectification results in significant energy loss. To reduce these losses, this paper proposes an AC boost circuit without additional power supply or rectifier bridge, designed for low-voltage electromagnetic energy harvesting. Both theoretical analysis and experimental results confirm the effectiveness of the proposed interface. The results show that the circuit can start self-excited boosting at an initial voltage of 0.48V and achieve an AC-DC conversion efficiency of 71.3 % within an input voltage range of 0–2.9V.